Doppler-free Yb Spectroscopy with Fluorescence Spot Technique

We demonstrate a simple technique to measure the resonant frequency of the 398.9 nm 1S0 - 1P1 transition for the different Yb isotopes. The technique, that works by observing and aligning fluorescence spots, has enabled us to measure transition frequencies and isotope shifts with an accuracy of 60 MHz. We provide wavelength measurements for the transition that differ from previously published work. Our technique also allows for the determination of Doppler shifted transition frequencies for photoionisation experiments when the atomic beam and laser beam are not perpendicular and furthermore allows us to determine the average velocity of the atoms along the direction of atomic beam

Bis-coumarins; non-cytotoxic selective urease inhibitors and antiglycation agents

© 2019 Elsevier Inc. The current study is concerned with the identification of lead molecules based on the bis-coumarin scaffold having selective urease inhibitory and antiglycation activities. For that purpose, bis-coumarins (1-44) were synthesized and structurally characterized by different spectroscopic techniques. Eight derivatives 4, 8-10, 14, 17, 34, and 40 demonstrated urease inhibition in the range of IC50 = 4.4 ± 0.21–115.6 ± 2.13 μM, as compared to standard thiourea (IC50 = 21.3 ± 1.3 μM). Especially, compound 17 (IC50 = 4.4 ± 0.21 μM) was found to be five-fold more potent than the standard. Kinetic studies were also performed on compound 17 in order to identify the mechanism of inhibition. Kinetic studies revealed that compound 17 is a competitive inhibitor. Antiglycation activity was evaluated using glycation of bovine serum albumin by methylglyoxal in vitro. Compounds 2, 11-13, 16, 17, 19–22, 35, 37, and 42 showed good to moderate antiglycation activities with IC50 values of 333.63–919.72 μM, as compared to the standard rutin (IC50 = 294.46 ± 1.5 μM). Results of both assays showed that the compounds with urease inhibitory activity did not show any antiglycation potential, and vice versa. Only compound 17 showed dual inhibition potential. All compounds were also evaluated for cytotoxicity. Compounds 17, 19, and 37 showed a weak toxicity towards 3 T3 mouse fibroblast cell line. All other compounds were found to be non-cytotoxic. Urease inhibition is an approach to treat infections caused by ureolytic bacteria whereas inhibition of glycation of proteins is a strategy to avoid late diabetic complications. Therefore, these compounds may serve as leads for further research

Optimum electrode configurations for fast ion separation in microfabricated surface ion traps

For many quantum information implementations with trapped ions, effective shuttling operations are important. Here we discuss the efficient separation and recombination of ions in surface ion trap geometries. The maximum speed of separation and recombination of trapped ions for adiabatic shuttling operations depends on the secular frequencies the trapped ion experiences in the process. Higher secular frequencies during the transportation processes can be achieved by optimising trap geometries. We show how two different arrangements of segmented static potential electrodes in surface ion traps can be optimised for fast ion separation or recombination processes. We also solve the equations of motion for the ion dynamics during the separation process and illustrate important considerations that need to be taken into account to make the process adiabatic

Sex-Based Differences in Inpatient Burn Mortality

Background: Among burn patients, research is conflicted, but may suggest that females are at increased risk of mortality, despite the opposite being true in non-burn trauma. Our objective was to determine whether sex-based differences in burn mortality exist, and assess whether patient demographics, comorbid conditions, and injury characteristics explain said differences. Methods: Adult patients admitted with burn injury—including inhalation injury only—between 2004 and 2013 were included. Inverse probability of treatment weights (IPTW) and inverse probability of censor weights (IPCW) were calculated using admit year, patient demographics, comorbid conditions, and injury characteristics to adjust for potential confounding and informative censoring. Standardized Kaplan–Meier survival curves, weighted by both IPTW and IPCW, were used to estimate the 30-day and 60-day risk of inpatient mortality across sex. Results: Females were older (median age 44 vs. 41 years old, p < 0.0001) and more likely to be Black (32% vs. 25%, p < 0.0001), have diabetes (14% vs. 10%, p < 0.0001), pulmonary disease (14% vs. 7%, p < 0.0001), heart failure (4% vs. 2%, p = 0.001), scald burns (45% vs. 26%, p < 0.0001), and inhalational injuries (10% vs. 8%, p = 0.04). Even after weighting, females were still over twice as likely to die after 60 days (RR 2.87, 95% CI 1.09, 7.51). Conclusion: Female burn patients have a significantly higher risk of 60-day mortality, even after accounting for demographics, comorbid conditions, burn size, and inhalational injury. Future research efforts and treatments to attenuate mortality should account for these sex-based differences. The project was supported by the National Institutes of Health, Grant Number UL1TR001111

Microfabricated Ion Traps

Ion traps offer the opportunity to study fundamental quantum systems with high level of accuracy highly decoupled from the environment. Individual atomic ions can be controlled and manipulated with electric fields, cooled to the ground state of motion with laser cooling and coherently manipulated using optical and microwave radiation. Microfabricated ion traps hold the advantage of allowing for smaller trap dimensions and better scalability towards large ion trap arrays also making them a vital ingredient for next generation quantum technologies. Here we provide an introduction into the principles and operation of microfabricated ion traps. We show an overview of material and electrical considerations which are vital for the design of such trap structures. We provide guidance in how to choose the appropriate fabrication design, consider different methods for the fabrication of microfabricated ion traps and discuss previously realized structures. We also discuss the phenomenon of anomalous heating of ions within ion traps, which becomes an important factor in the miniaturization of ion traps

Engineering of microfabricated ion traps and integration of advanced on-chip features

Atomic ions trapped in electromagnetic potentials have long been used for fundamental studies in quantum physics. Over the past two decades, trapped ions have been successfully used to implement technologies such as quantum computing, quantum simulation, atomic clocks, mass spectrometers and quantum sensors. Advanced fabrication techniques, taken from other established or emerging disciplines, are used to create new, reliable ion-trap devices aimed at large-scale integration and compatibility with commercial fabrication. This Technical Review covers the fundamentals of ion trapping before discussing the design of ion traps for the aforementioned applications. We overview the current microfabrication techniques and the various considerations behind the choice of materials and processes. Finally, we discuss current efforts to include advanced, on-chip features in next-generation ion traps

Effect of tube material on convective heat transfer of various nanofluids

This work presents the convective heat transfer and friction loss characteristics of novel functionalized graphene-based and metal oxide nanofluids. The convective heat transfer in circular tubes of different materials (copper, aluminium and stainless steel 316) was used at constant wall heat flux of 23,870 W m−2. An innovative approach was used to prepare highly dispersed propylene glycol-treated graphene nanoplatelets–water (GNP1) and trimethylolpropane tris amine–water (GNP2) by functionalization method. The measured thermal conductivity of GNP1 and GNP2 nanofluids showed incredible performance which increased up to 32% and 31% higher than that of basefluid. By comparing material effect, copper tube showed the highest HTC up to 119% in GNP1 at 0.1 mass%, while in aluminium and stainless steel 316 tube the highest heat transfer coefficient (HTC) was 110.2% and 100.68%. Besides, alumina and silicon dioxide nanofluids also presented decent increment in HTC which was up to 29.1% and 31.6%, respectively. The highest rise in friction factor for GNP1 and GNP2 was obtained up to 10.2% and 10%, respectively. For alumina and silicon dioxide nanofluids, the friction factor was measured up to 5.92% and 7.14% at velocity range of 1–3 m s−1. The maximum enhancement in Nusselt number (Nu) for GNP, GNP2, alumina and silicon dioxide nanofluids was achieved up to 84%, 72%, 26% and 28%. The results suggest that the copper tube which is a good conductor of heat could be used in the heat exchangers and functionalized GNP nanofluids can be used as the heat exchanging fluids in heat transfer applications which could give a decent substitute to traditional working fluids in heat exchangers and in thermal fluid systems

Modelling for Uncertainties in Resistance for Jacket Platforms in Malaysia

Abstract: Structural design strength is based on characteristic values of basic random variables of resistance. The behavior of these variables of strength may vary in such a way that they become unsafe during any time of their design life. The data for this study was collected from an ISO certified fabrication yard in Malaysia and was used to make statistical models. The collected data is based on jackets which were under construction at the yard. Statistical analysis of the data was performed, taking into account the mean, coefficient of variation and bias values. Initially basic random variables were analyzed and after their statistical parameters were found, the basic stresses were simulated based on ISO 19902 code equations. Finally recommendations are made for the statistical characteristics of the random variables to be used in this region for the reliability analysis for tubular members and joints for ultimate limit state design of jacket platforms in Malaysia

Effect of Application of Micronutrients on Spotted Bollworm Earias vittella (Fabricius), Infestation and Yield Components in Cotton Crop

Studies were carried out on the effect of micronutrients on spotted bollworm, Earias vittella F. infestation and yield components in cotton crop under field conditions. Cotton variety (CRIS-134) was sown in randomized block design with seven treatments including control (check) and was replicated three times on May 22, 2004-2005. Three micronutrients Bonus®, Dawn ®and Power® were applied three times at 79, 95 and 109 days after sowing. The results indicated that there was no significant effect of removal of leaves and fruiting bodies on infestation of bollworm. However, application of micronutrients significantly affected the bollworm infestation. There was significant effect of micro-nutrients on boll volume and opening of bolls in different micronutrients applied plots. The maximum yield was obtained from Bonus® applied plots than other micronutrients applied plots